diff --git a/Lib/test/test_abstract_numbers.py b/Lib/test/test_abstract_numbers.py
index 2e06f0d16fdd05..f8075339fd42a2 100644
--- a/Lib/test/test_abstract_numbers.py
+++ b/Lib/test/test_abstract_numbers.py
@@ -3,6 +3,7 @@
 import math
 import operator
 import unittest
+from random import random
 from numbers import Complex, Real, Rational, Integral
 
 class TestNumbers(unittest.TestCase):
@@ -40,5 +41,92 @@ def test_complex(self):
         self.assertRaises(TypeError, int, c1)
 
 
+class TestAbstractNumbers(unittest.TestCase):
+    def testComplex(self):
+
+        class SubComplex(Complex):
+            def __complex__(self):
+                pass
+
+            @property
+            def real(self):
+                return self._imag
+
+            @property
+            def imag(self):
+                return self._real
+
+            def __add__(self, other):
+                pass
+
+            def __radd__(self, other):
+                pass
+
+            def __neg__(self):
+                pass
+
+            def __pos__(self):
+                pass
+
+            def __mul__(self, other):
+                pass
+
+            def __rmul__(self, other):
+                pass
+
+            def __truediv__(self, other):
+                pass
+
+            def __rtruediv__(self, other):
+                pass
+
+            def __pow__(self, exponent):
+                pass
+
+            def __rpow__(self, base):
+                pass
+
+            def __abs__(self):
+                pass
+
+            def conjugate(self):
+                pass
+
+            def __init__(self, r, i):
+                self.real = r
+                self.imag = i
+
+            def __eq__(self, other):
+                return isinstance(other, SubComplex) and self.imag == other.imag and self.real == other.real
+
+            @imag.setter
+            def imag(self, value):
+                self._imag = value
+
+            @real.setter
+            def real(self, value):
+                self._real = value
+
+        sc = SubComplex(0,0)
+        self.assertIsInstance(sc, Complex)
+
+        nonInstances = [None, "hat", lambda x: x + 1]
+
+        for nonInstance in nonInstances:
+            self.assertNotIsInstance(nonInstance, Complex)
+
+        self.assertFalse(SubComplex.__bool__(0))
+        for i in range(100):
+            self.assertTrue(SubComplex.__bool__(random() + 1e-6))
+            x = random()
+            y = random()
+            self.assertEqual(SubComplex.__sub__(x, y), x - y)
+            self.assertEqual(SubComplex.__rsub__(x, y), - x + y)
+            sc1 = SubComplex(x, y)
+            sc2 = SubComplex(x, y)
+            self.assertEqual(sc1, sc2)
+            self.assertNotEqual(x, y + 1e-6)
+
+
 if __name__ == "__main__":
     unittest.main()